--- /dev/null
+From tiwai@suse.de Wed Nov 7 15:57:25 2012
+From: tiwai@suse.de
+Date: Wed, 7 Nov 2012 12:39:53 +0100
+Subject: ALSA: usb-audio: Use rwsem for disconnect protection
+To: stable@vger.kernel.org
+
+From: Takashi Iwai <tiwai@suse.de>
+
+commit 34f3c89fda4fba9fe689db22253ca8db2f5e6386 upstream.
+
+Replace mutex with rwsem for codec->shutdown protection so that
+concurrent accesses are allowed.
+
+Also add the protection to snd_usb_autosuspend() and
+snd_usb_autoresume(), too.
+
+Reported-by: Matthieu CASTET <matthieu.castet@parrot.com>
+Signed-off-by: Takashi Iwai <tiwai@suse.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ sound/usb/card.c | 12 ++++++++----
+ sound/usb/mixer.c | 12 ++++++------
+ sound/usb/pcm.c | 12 ++++++------
+ sound/usb/usbaudio.h | 2 +-
+ 4 files changed, 21 insertions(+), 17 deletions(-)
+
+--- a/sound/usb/card.c
++++ b/sound/usb/card.c
+@@ -339,7 +339,7 @@ static int snd_usb_audio_create(struct u
+ }
+
+ mutex_init(&chip->mutex);
+- mutex_init(&chip->shutdown_mutex);
++ init_rwsem(&chip->shutdown_rwsem);
+ chip->index = idx;
+ chip->dev = dev;
+ chip->card = card;
+@@ -560,7 +560,7 @@ static void snd_usb_audio_disconnect(str
+
+ card = chip->card;
+ mutex_lock(®ister_mutex);
+- mutex_lock(&chip->shutdown_mutex);
++ down_write(&chip->shutdown_rwsem);
+ chip->shutdown = 1;
+ chip->num_interfaces--;
+ if (chip->num_interfaces <= 0) {
+@@ -582,11 +582,11 @@ static void snd_usb_audio_disconnect(str
+ snd_usb_mixer_disconnect(p);
+ }
+ usb_chip[chip->index] = NULL;
+- mutex_unlock(&chip->shutdown_mutex);
++ up_write(&chip->shutdown_rwsem);
+ mutex_unlock(®ister_mutex);
+ snd_card_free_when_closed(card);
+ } else {
+- mutex_unlock(&chip->shutdown_mutex);
++ up_write(&chip->shutdown_rwsem);
+ mutex_unlock(®ister_mutex);
+ }
+ }
+@@ -618,16 +618,20 @@ int snd_usb_autoresume(struct snd_usb_au
+ {
+ int err = -ENODEV;
+
++ down_read(&chip->shutdown_rwsem);
+ if (!chip->shutdown && !chip->probing)
+ err = usb_autopm_get_interface(chip->pm_intf);
++ up_read(&chip->shutdown_rwsem);
+
+ return err;
+ }
+
+ void snd_usb_autosuspend(struct snd_usb_audio *chip)
+ {
++ down_read(&chip->shutdown_rwsem);
+ if (!chip->shutdown && !chip->probing)
+ usb_autopm_put_interface(chip->pm_intf);
++ up_read(&chip->shutdown_rwsem);
+ }
+
+ static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
+--- a/sound/usb/mixer.c
++++ b/sound/usb/mixer.c
+@@ -292,7 +292,7 @@ static int get_ctl_value_v1(struct usb_m
+ err = snd_usb_autoresume(cval->mixer->chip);
+ if (err < 0)
+ return -EIO;
+- mutex_lock(&chip->shutdown_mutex);
++ down_read(&chip->shutdown_rwsem);
+ while (timeout-- > 0) {
+ if (chip->shutdown)
+ break;
+@@ -310,7 +310,7 @@ static int get_ctl_value_v1(struct usb_m
+ err = -EINVAL;
+
+ out:
+- mutex_unlock(&chip->shutdown_mutex);
++ up_read(&chip->shutdown_rwsem);
+ snd_usb_autosuspend(cval->mixer->chip);
+ return err;
+ }
+@@ -337,7 +337,7 @@ static int get_ctl_value_v2(struct usb_m
+ if (ret)
+ goto error;
+
+- mutex_lock(&chip->shutdown_mutex);
++ down_read(&chip->shutdown_rwsem);
+ if (chip->shutdown)
+ ret = -ENODEV;
+ else {
+@@ -346,7 +346,7 @@ static int get_ctl_value_v2(struct usb_m
+ USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
+ validx, idx, buf, size);
+ }
+- mutex_unlock(&chip->shutdown_mutex);
++ up_read(&chip->shutdown_rwsem);
+ snd_usb_autosuspend(chip);
+
+ if (ret < 0) {
+@@ -453,7 +453,7 @@ int snd_usb_mixer_set_ctl_value(struct u
+ err = snd_usb_autoresume(chip);
+ if (err < 0)
+ return -EIO;
+- mutex_lock(&chip->shutdown_mutex);
++ down_read(&chip->shutdown_rwsem);
+ while (timeout-- > 0) {
+ if (chip->shutdown)
+ break;
+@@ -471,7 +471,7 @@ int snd_usb_mixer_set_ctl_value(struct u
+ err = -EINVAL;
+
+ out:
+- mutex_unlock(&chip->shutdown_mutex);
++ up_read(&chip->shutdown_rwsem);
+ snd_usb_autosuspend(chip);
+ return err;
+ }
+--- a/sound/usb/pcm.c
++++ b/sound/usb/pcm.c
+@@ -474,7 +474,7 @@ static int snd_usb_hw_params(struct snd_
+ subs->period_bytes != params_period_bytes(hw_params) ||
+ subs->cur_rate != rate;
+
+- mutex_lock(&subs->stream->chip->shutdown_mutex);
++ down_read(&subs->stream->chip->shutdown_rwsem);
+ if (subs->stream->chip->shutdown) {
+ ret = -ENODEV;
+ goto unlock;
+@@ -512,7 +512,7 @@ static int snd_usb_hw_params(struct snd_
+ }
+
+ unlock:
+- mutex_unlock(&subs->stream->chip->shutdown_mutex);
++ up_read(&subs->stream->chip->shutdown_rwsem);
+ return ret;
+ }
+
+@@ -528,12 +528,12 @@ static int snd_usb_hw_free(struct snd_pc
+ subs->cur_audiofmt = NULL;
+ subs->cur_rate = 0;
+ subs->period_bytes = 0;
+- mutex_lock(&subs->stream->chip->shutdown_mutex);
++ down_read(&subs->stream->chip->shutdown_rwsem);
+ if (!subs->stream->chip->shutdown) {
+ stop_endpoints(subs, 0, 1, 1);
+ deactivate_endpoints(subs);
+ }
+- mutex_unlock(&subs->stream->chip->shutdown_mutex);
++ up_read(&subs->stream->chip->shutdown_rwsem);
+ return snd_pcm_lib_free_vmalloc_buffer(substream);
+ }
+
+@@ -553,7 +553,7 @@ static int snd_usb_pcm_prepare(struct sn
+ return -ENXIO;
+ }
+
+- mutex_lock(&subs->stream->chip->shutdown_mutex);
++ down_read(&subs->stream->chip->shutdown_rwsem);
+ if (subs->stream->chip->shutdown) {
+ ret = -ENODEV;
+ goto unlock;
+@@ -582,7 +582,7 @@ static int snd_usb_pcm_prepare(struct sn
+ ret = start_endpoints(subs, 1);
+
+ unlock:
+- mutex_unlock(&subs->stream->chip->shutdown_mutex);
++ up_read(&subs->stream->chip->shutdown_rwsem);
+ return ret;
+ }
+
+--- a/sound/usb/usbaudio.h
++++ b/sound/usb/usbaudio.h
+@@ -37,7 +37,7 @@ struct snd_usb_audio {
+ struct usb_interface *pm_intf;
+ u32 usb_id;
+ struct mutex mutex;
+- struct mutex shutdown_mutex;
++ struct rw_semaphore shutdown_rwsem;
+ unsigned int shutdown:1;
+ unsigned int probing:1;
+ unsigned int autosuspended:1;
projects / thirdparty / kernel / stable-queue.git / blobdiff